Early implant failure. Prognostic capacity of Periotest: retrospective study of a large sample

Objectives: The objectives of this study were to determine the accuracy of Periotest^® to monitor primary implant stability at first‐stage surgery, to identify by multivariate analysis the variables associated with early implant failure and to compare Periotest^® with radiographic study in the diagnosis of implant stability at second‐stage surgery (during osseointegration period). Material and methods: A 10‐year retrospective study was conducted on 1084 Brånemark^® implants placed in 316 patients. Clinical variables, implant diameter and length, Periotest^® values (PTVs) and radiological variables were analyzed in bivariate and multivariate studies in order to determine their influence on early implant failure. Results: After examination of the sensitivity and specificity values obtained for different PTV cutoff points, a cutoff PTV of ?2 was selected (84% sensitivity and 39% specificity). In the bivariate analysis, early failure was significantly related to smoking habits, implant location, bone type, implant features and PTVs (?2 and ≥?2). In the final multiple logistic model, only age (odds ratio (OR)=4.53; 95% confidence interval (CI), 1.34–15.27), smoking habits (OR=2.5; 95% CI, 1.3–4.79), bone type (OR=1.93; 95% CI, 1.01–3.7) and PTV at first surgery (OR=3.01; 95% CI, 1.5–6.02) were independently related to early failure. Conclusions: The Periotest^® (with ?2 cutoff) at first surgery offers high sensitivity in the prognosis of early implant loss and shows a greater capacity to evaluate stability during the osseointegration period compared with radiographic study.     

Proton Pump Inhibitors and the Risk of Osseointegrated Dental Implant Failure: A Cohort Study

Proton pump inhibitors (PPIs) have a negative impact on bone accrual. Because osseointegration is influenced by bone metabolism, this study investigates the association between PPIs and the risk of osseointegrated implant failure. This retrospective cohort study included a total of 1,773 osseointegrated dental implants in 799 patients (133 implants in 58 PPIs users and 1,640 in 741 non‐users) who were treated at the East Coast Oral Surgery Clinic in Moncton, Canada, from January 2007 to September 2015. Kaplan‐Meier estimator was used to describe the hazard function of dental implant failure by PPIs usage. Multilevel mixed effects parametric survival analyses were used to test the association between PPIs exposure and risk of implant failure adjusting for potential confounders. The failure rates were 6.8% for people using PPIs compared to 3.2% for non‐users. Subjects using PPIs had a higher risk of dental implant failure (HR = 2.73; 95% CI = 1.10–6.78) compared to those who did not use the drugs. The findings suggest that treatment with PPIs may be associated with an increased risk of osseointegrated dental implant failure.     

Interventions for Dental Implant Placement in Atrophic Edentulous Mandibles: Vertical Bone Augmentation and Alternative Treatments. A Meta‐Analysis of Randomized Clinical Trials

Background: The purpose of the current study is to assess which vertical bone augmentation techniques are most effective for restoring atrophic posterior areas of the mandible with dental implants and compare these procedures with alternative treatments. Methods: Electronic literature searches in PubMed (MEDLINE), Ovid, and the Cochrane Library were conducted to identify all relevant articles published up to July 1, 2015. Eligibility was based on inclusion criteria, and quality assessments were conducted. The primary outcome variables were implant and prosthetic failure. After data extraction, meta‐analyses were performed. Results: Out of 527 potentially eligible papers, 14 randomized clinical trials were included. Out of these 14 studies, four trials assessed short implants (5 to 8 mm) as an alternative to vertical bone augmentation in sites with a residual ridge height of 5 to 8 mm. No statistically significant differences were found in implant (odds ratio [OR]: 1.02; 95% confidence interval [CI]: 0.31 to 3.31; P = 0.98; I²: 0%) or prosthetic failure (OR: 0.64; 95% CI: 0.21 to 1.96; P = 0.43; I²: 0%) after 12 months of loading. However, complications at treated sites increased with the augmentation procedures (OR: 8.33; 95% CI: 3.85 to 20.0; P <0.001; I²: 0%). There was no evidence of any vertical augmentation procedure being of greater benefit than any other for the primary outcomes (implant and prosthetic failure). Conclusions: Short implants in the posterior area of the mandible seem to be preferable to vertical augmentation procedures, which present similar implant and prosthetic failure rates but greater morbidity. All the vertical augmentation technique comparisons showed similar intergroup results.     

Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects

Objective: This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite® with that around Nanotite^? implants. Materials and methods: The premolars on both sides of the mandible in four beagle dogs were extracted. Following 4 months healing, two Nanotite^? implants and two Osseotite® implants were partially inserted in the left side of each mandible. Some threads protruded from the tissues into the oral cavity. Following a 5 week healing period, the implants were removed and the contaminated part of each implant was cleaned. They were then installed to the full implant length on the contra lateral side of the mandibles. The coronal 5 mm of each implant was surrounded by 1 mm circumferential bone defect. Following 12 weeks of healing period, the dogs were sacrificed and biopsies were obtained. Ground sections were prepared for histomorphometric analysis. Results: All implants were associated with direct bone‐to‐implant contact on the portion of the implant surface contaminated previously and surrounded by bone defect. Nanotite^? implants performed better than Osseotite® implants. Conclusions: The results demonstrated that implant surfaces, which were contaminated previously and were surrounded by bone defects, can osseointegrate. To cite this article:
Mohamed S, Polyzois I, Renvert S, Claffey N. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects. Clin. Oral Impl. Res. 21 , 2010; 513–519.
doi: 10.1111/j.1600‐0501.2010.01913.x     

Survival and failure rates of orthodontic temporary anchorage devices: a systematic review

Aim: The purpose of this study was to systematically review the literature on the survival rates of palatal implants, Onplants^®, miniplates and mini screws. Material and methods: An electronic MEDLINE search supplemented by manual searching was conducted to identify randomized clinical trials, prospective and retrospective cohort studies on palatal implants, Onplants^®, miniplates and miniscrews with a mean follow‐up time of at least 12 weeks and of at least 10 units per modality having been examined clinically at a follow‐up visit. Assessment of studies and data abstraction was performed independently by two reviewers. Reported failures of used devices were analyzed using random‐effects Poisson regression models to obtain summary estimates and 95% confidence intervals (CI) of failure and survival proportions. Results: The search up to January 2009 provided 390 titles and 71 abstracts with full‐text analysis of 34 articles, yielding 27 studies that met the inclusion criteria. In meta‐analysis, the failure rate for Onplants^® was 17.2% (95% CI: 5.9–35.8%), 10.5% for palatal implants (95% CI: 6.1–18.1%), 16.4% for miniscrews (95% CI: 13.4–20.1%) and 7.3% for miniplates (95% CI: 5.4–9.9%). Miniplates and palatal implants, representing torque‐resisting temporary anchorage devices (TADs), when grouped together, showed a 1.92‐fold (95% CI: 1.06–2.78) lower clinical failure rate than miniscrews. Conclusion: Based on the available evidence in the literature, palatal implants and miniplates showed comparable survival rates of ≥90% over a period of at least 12 weeks, and yielded superior survival than miniscrews. Palatal implants and miniplates for temporary anchorage provide reliable absolute orthodontic anchorage. If the intended orthodontic treatment would require multiple miniscrew placement to provide adequate anchorage, the reliability of such systems is questionable. For patients who are undergoing extensive orthodontic treatment, force vectors may need to be varied or the roots of the teeth to be moved may need to slide past the anchors. In this context, palatal implants or miniplates should be the TADs of choice.     

Postoperative infections after dental implant placement: Variables associated with increased risk of failure

1 Background

Wound infections after dental implant placement are a rare finding that might lead to early implant failure. However, the available information on this topic is scarce.

2 Methods

This retrospective cohort study was conducted to determine factors that may increase the failure rate of dental implants that presented a postoperative infection during the osseointegration period. Postoperative infections were defined as the presence of pus or fistula in the surgical area, with pain or tenderness, swelling, redness, and heat or fever, before prosthetic loading. A bivariate and multivariate analysis of the data using Cox proportional‐hazards regression was performed to detect prognostic factors for implant failure in patients that suffer infections.

3 Results

The patient‐based prevalence of postoperative infections after implant placement was 2.80% (95% confidence interval (95%CI): 2.04% to 3.83%). Thirty‐three out of 37 (89.19%) patients with infections had to be surgically retreated because of antibiotic failure and 65% of the infected implants were removed. The bivariate analysis showed a significant association between implant failure and the collar surface (HR: 3.12; 95% CI: 1.16 to 8.41; P = 0.014). Cox proportional‐hazards regression indicated that rough‐surfaced collars increased 2.35 times the likelihood of failure (95% CI: 0.87 to 6.37; P = 0.071).

4 Conclusions

The survival of implants placed in the maxilla, with smooth collar, and late‐onset of infection was higher than those placed in the mandible, with a rough collar and early onset of infection. In general, signs of infection after dental implant placement compromises the survival rate of the affected fixtures.     

COVID-19 as a factor associated with early dental implant failures: A retrospective analysis

Objectives

To analyze the effect of COVID-19 on early implant failures and identify potential risk factors for early implant failure, concerning patient- and implant-related factors.

Materials and Methods

This retrospective study is based on 1228 patients who received 4841 implants between March 11, 2020, and April 01, 2022, at Erciyes University Faculty of Dentistry. COVID-19, age and gender of patients, smoking, diabetes, irradiation, chemotherapy, osteoporosis, the implant system, location, and characteristics of implants were recorded. At the implant level, univariate and multivariate generalized estimating equation (GEE) logistic regression was used to examine the effect of explanatory variables on early implant failure.

Results

The early implant failure rate was 3.1% at the implant level and 10.4% at the patient level. Smokers showed a significantly higher incidence of early implant failures compared to nonsmokers. (odds ratio (OR; 95% CI): 2.140 (1.438–3.184); p < 0.001). Short implants (≤8 mm) had a higher risk of early implant failure than long implants (≥12 mm) (OR (95% CI): 2.089 (1.290–3.382); p = 0.003).

Conclusions

COVID-19 had no significant effect on early implant failure. Smoking and short implants were associated with a higher risk for early implant failures.     

A field trial of resin-based and glass-ionomer fissure sealants: clinical and radiographic assessment of caries

Abstract – Objective: The purpose of the present study was to provide further data for comparison of retention and caries‐preventive effect of a resin‐based sealant (Delton^®), and a glass–ionomer sealant (Fuji III^®). Methods: The study was conducted in the municipality of Værløse located 15 km north of Copenhagen, Denmark in the period 1996–2001. The study comprised 153 children aged 8–13 years with a total of 364 site‐pairs. Caries was diagnosed both clinically and radiographically, and sealant retention was diagnosed clinically. Sealants were placed either by one of four dentists, who had the responsibility for the children's dental care, by a dental hygienist or a dental assistant. Mean follow‐up time was 38–39 months for sites on first permanent molars and 28–29 months for sites on second permanent molars. Results: The retention rates were consistently, and considerably lower for Fuji III^® than for Delton^®. Relative risks of caries in Delton^®‐sealed teeth over Fuji III^®‐sealed teeth was 0.435 (95% CI 0.150–0.846) based on the clinical diagnosis, and 0.559 (95% CI 0.342–0.905) based on the radiographic diagnosis. The ratio of the relative risks (clinical over radiographic diagnosis) was close to 1 (0.778; 95% CI 0.272–1.481). Conclusion: In the present study, Delton^®‐sealed teeth had a lower risk than Fuji III^®‐sealed teeth of developing caries, independent of the caries diagnostic method used.     

A comparison of two implant techniques on patient‐based outcome measures: a report of flapless vs. conventional flapped implant placement

Background: Flapless implant surgery is considered to offer advantages over the traditional flap access approach. There may be minimized bleeding, decreased surgical times and minimal patient discomfort. Controlled studies comparing patient outcome variables to support these assumptions, however, are lacking. Aim: The objective of this clinical study was to compare patient outcome variables using flapless and flapped implant surgical techniques. Patients and methods: From January 2008 to October 2008, 16 consecutive patients with edentulous maxillas were included in the study. Patients were randomly allocated to either implant placement with a flapless procedure (eight patients, mean age 54.6±2.9 years) or surgery with a conventional flap procedure (eight patients, mean age 58.7±7.2 years). All implants were placed using a Nobel guide^® CT‐guided surgical template. Outcome measures were the Dutch version of the Impact of Event Scale‐Revised (IES‐R), dental anxiety using the s‐DAI and oral health‐related quality of life (OHIP‐14). Results: Ninety‐six implants were successfully placed. All implants were placed as two‐phase implants and the after‐implant placement dentures were adapted. No differences could be shown between conditions on dental anxiety (s‐DAI), emotional impact (IES‐R), anxiety, procedure duration or technical difficulty, although the flapless group did score consistently higher. The flap procedure group reported less impact on quality of life and included more patients who reported feeling no pain at all during placement. Conclusions: Differences found in the patient outcome variables do suggest that patients in the flapless implant group had to endure more than patients in the flap group. To cite this article:
Lindeboom JA, van Wijk AJ. A comparison of two implant techniques on patient‐based outcome measures: a report of flapless vs. conventional flapped implant placement.
Clin. Oral Impl. Res. 21 , 2010; 366–370.
doi: 10.1111/j.1600‐0501.2009.01866.x     

The Effect of Smoking on Early Bone Remodeling on Surface Modified Southern Implants®

Introduction: Smoking affects the survival of turned titanium implants. Although smoking has less impact on the failure rate of rough surface implants, the effect on bone loss on rough surface implants has not been studied yet and may be an important factor in biological stability. Aim: To determine the effect of smoking on early implant failures and bone remodeling around moderately rough implants (Southern Implants®, Southern Implants, Irene, South Africa). Materials and Methods: Three hundred twenty‐nine patient records, containing information on 712 installed implants, were scrutinized retrospectively and periapical radiographs were analyzed for interproximal bone level. Mann‐Whitney U‐test and Fisher's exact test were performed to compare bone level and implant survival in smokers and nonsmokers. Only implants with at least 6 months of function time were analyzed for bone level changes. Results: The overall survival rate was 98.3%. Implants in smokers had a threefold higher failure rate compared with nonsmokers (5/104 = 4.8% vs 7/608 = 1.2%). This was statistically significant on implant level (p = .007) but not on patient level (1/41 vs 7/288, p = .997). Readable radiographs from 363 implants in 169 patients were available with a mean follow‐up of 12 months (SD 5.11; range 6–28). The mean interproximal bone level was 1.36 mm (n = 363; SD 0.41; range 0.48–3.70). Bone levels were independent of jaw location. Sixty implants from 21 smokers lost statistically significantly (p = .001) more bone (mean 1.56; SD 0.53; range 0.75–3.22) than the 303 implants in 148 nonsmokers (mean 1.32 mm; SD 0.38; range 0.48–3.7). The maxilla is especially prone to bone loss compared with the mandible (1.70 mm vs 1.26 mm, p < .001). Conclusion: The Southern Implants® system demonstrated a high absolute survival rate. Although smokers are not more prone to implant loss, more pronounced peri‐implant bone loss was observed, especially in the maxilla. Whether this affects future biological complications remains to be investigated in prospective long‐term studies.     

Outcomes of osseointegrated implants in patients with benign and malignant pathologies of the head and neck: a 10-year single-centre study

The surgical management of head and neck pathologies involving the maxilla and mandible results in significant functional and aesthetic deficits, and ultimately reduced quality of life. Composite free flaps used for reconstruction address many of these deficits and create a foundation for the use of osseointegrated implants to support prosthetic replacement of the dentition. There are few comparative studies examining outcomes of implants in native and reconstructed bone in head and neck cancer patients. The aim of this retrospective cohort study was to compare survival rates and the effects of risk factors between implants placed in native and reconstructed bone. The Kaplan–Meier method estimated cumulative 1- and 5-year implant survival rates of 99.5% and 95% for native bone and 96% and 88% for reconstructed bone. Multivariate Cox regression found an increased risk of implant failure in reconstructed bone (hazard ratio (HR) 9.9, 95% confidence interval (CI) 3.4–29.7, P < 0.001). Subgroup analysis of the cohorts found an increased risk of failure in the reconstructed group associated with radiotherapy (HR 6.4, 95% CI 1.8–22.3, P = 0.004), current smoking (HR 23.2, 95% CI 2.7–198.6, P = 0.004), and previous smoking (HR 9.0, 95% CI 1.1–71.9, P = 0.038). There was no effect in the native bone group. Implants placed into reconstructed bone had higher rates of failure, and smoking status and radiotherapy increased the risk of implant failure.     

Clinical performance of provisional screw‐retained metal‐free acrylic restorations in an immediate loading implant protocol: a 242 consecutive patients' report

Objective: To evaluate the clinical performance of provisional screw‐retained metal‐free acrylic restorations in an immediate loading implant protocol. Material and methods: Two hundred and forty‐two consecutive patients were selected retrospectively, who received 1011 implants and 311 immediate provisional screw‐retained implant restorations (2–4 h after implant surgery). The patients were monitored for a period of 2–3 months, until they were referred for a final restoration. The primary variables recorded include the survival time and the appearance of fractures in the provisional restoration, and the independent variables included age, sex, dental arch, type of restoration, type of attachment and components used, as well as cantilevers and opposing dentition. A survival analysis (Kaplan–Meier) and a Cox regression analysis were performed. Results: Twenty‐three restorations in 20 patients (8.26%, 95% CI 4.8–11.7) showed at least one fracture (7.39%). More than half of the new fractures (52%, 12 cases) occurred in the first 4 weeks. The cumulative survival probability observed was greater in mandible (P=0.05) and non‐cantilever restorations (P=0.001), and in those opposed by full restorations or natural teeth (P=0.001). With an opposing implant‐supported prosthesis, the risk of fracture was multiplied by 4.7, and the use of cantilevers as well as the location of the restoration in the maxilla multiply the risk by 3.4–3.5. Conclusions: Immediate provisional screw‐retained metal‐free implant‐supported restorations can be considered a reliable restoration (92.6% remain intact) for the healing period of 3 months. To cite this article:
Suarez‐Feito JM, Sicilia A, Angulo J, Banerji S, Cuesta I, Millar B. Clinical performance of provisional screw‐retained metal‐free acrylic restorations in an immediate loading implant protocol: a 242 consecutive patients' report.
Clin. Oral Impl. Res. 21 , 2010; 1360–1369.
doi: 10.1111/j.1600‐0501.2010.01956.x     

Patient satisfaction with mini‐implant stabilised full dentures. A 1‐year prospective study

The purpose of this study was to evaluate patient‐centred outcomes with regard to function and comfort after placement of mini‐implants for stabilisation of complete dentures. The trial was designed as a prospective cohort of 12‐months duration and involved 21 subjects in the age of 50–90 years having a full denture in the maxilla or the mandible with poor stability during function. Flapless installation of 2–4 narrow‐body Dentatus Atlas^® implants was performed and retention for the existing denture was obtained by the use of a silicone‐based soft lining material (Tuf‐Link^®). Patients' judgement of perceived satisfaction with function and comfort of the dentures was recorded at baseline, 1‐ and 12‐months post‐treatment using 10‐centimetre visual analogue scales (VAS) and a questionnaire. Clinical examination of the conditions of the peri‐implant soft tissues was performed at 12 months. Nineteen of the 21 patients were available for the 12‐month follow‐up examination. The two drop‐out subjects lost all implants within 1 month and rejected retreatment. Further six subjects lost 1–2 implants, but were sucessfully retreated by insertion of new implants. Overall satisfaction, chewing and speaking comfort were all markedly improved from pre‐treatment median VAS scores of around 4–5 to median scores of 9·0–10 (10 = optimal) at the final examination. The prevalence of positive answers to questions regarding stability/function of the denture increased significantly to almost 100% for all questions. Treatment involving maxillary dentures and the use of short implants (7–10 mm) was associated with an increased risk of implant failure. The results indicate that placement of mini‐implants as retentive elements for full dentures with poor functional stability has a marked positive impact on the patients' perception of oral function and comfort as well as security in social life.     

Prophylactic antibiotic regimen and dental implant failure: a meta‐analysis

The aim of this meta‐analysis was to investigate whether there are any positive effects of prophylactic antibiotic regimen on implant failure rates and post‐operative infection when performing dental implant treatment in healthy individuals. An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomised or not. The search strategy resulted in 14 publications. The I² statistic was used to express the percentage of the total variation across studies due to heterogeneity. The inverse variance method was used with a fixed‐ or random‐effects model, depending on the heterogeneity. The estimates of relative effect were expressed in risk ratio (RR) with 95% confidence interval. Six studies were judged to be at high risk of bias, whereas one study was considered at moderate risk, and six studies were considered at low risk of bias. The test for overall effect showed that the difference between the procedures (use versus non‐use of antibiotics) significantly affected the implant failure rates (P = 0·0002), with a RR of 0·55 (95% CI 0·41–0·75). The number needed to treat (NNT) to prevent one patient having an implant failure was 50 (95% CI 33–100). There were no apparent significant effects of prophylactic antibiotics on the occurrence of post‐operative infections in healthy patients receiving implants (P = 0·520). A sensitivity analysis did not reveal difference when studies judged as having high risk of bias were not considered. The results have to be interpreted with caution due to the presence of several confounding factors in the included studies.     

Early loading of implants with fixed dental prostheses in edentulous mandibles: 4.5‐year clinical results from a prospective study

Aim: The purpose of this study was to evaluate the survival and success of early‐loaded implants placed in the intraforaminal area of the edentulous mandible, and the survival of the implant‐supported fixed dental prostheses (FDP). Material and methods: Thirty‐seven patients (18.9% male, mean age 64.5 years) with edentulous lower jaws were treated with implant‐supported FDPs in the mandible. One hundred and eighty‐five screw‐type implants were placed in the intraforaminal area of the symphysis (five implants per patient). Immediately after implant placement, a framework was fabricated and the FDP was manufactured on the framework. Within 2 weeks, the implants were rigidly connected and loaded with the implant‐retained FDP. Results: During the 1–8‐year observation period (mean 4.5 years), a total of 32 implant‐retained complications occurred. Nineteen implants were lost in 10 patients, resulting in a cumulative survival of 89.7%. Nine implants in five patients did not osseointegrate. Although these implants were not removed, because stability within the connective tissue was acceptable and inflammation was absent, they were recorded as unsuccessful. Consequently, the cumulative success declined to 84.9%. Four implants in three patients had clinical signs of periimplantitis (2.2% of all implants). Denture‐related complications included one complete failure, when one FDP had to be removed after the last of five implants had been replaced. Furthermore, 10 fractures of the framework occurred in six patients, three FDPs had to be adapted or modified, and the facing of the FDP had to be repaired 16 times in 11 patients. Conclusion: Although one‐stage early‐loaded implants functioned well for most patients with edentulous mandibles, immediate loading is associated with a larger number of implant‐related complications than in other studies investigating delayed loading. Because of the substantial prosthetic complications and aftercare, this procedure cannot be generally recommended. To cite this article:
Schwarz S, Gabbert O, Hassel A J, Schmitter M, Séché C, Rammelsberg P. Early loading of implants with fixed dental prostheses in edentulous mandibles: 4.5‐year clinical results from a prospective study.
Clin. Oral Impl. Res. 21 , 2010; 284–289.
doi: 10.1111/j.1600‐0501.2009.01843.x     

Survival of dental implants in irradiated head and neck cancer patients: a retrospective analysis

Purpose: To study the long‐term survival of dental implants placed in irradiated bone in subjects who received radiation for head and neck cancer. Materials and Method: A retrospective chart review was conducted for all patients who received dental implants following radiation treatment for head and neck cancer between May 1, 1987 through July 1, 2008. Only patients irradiated with a radiation dose of 50 Gy or greater and those who received dental implants in the irradiated field after head and neck radiation were included in the study. The associations between implant survival and patient/implant characteristics were estimated by fitting univariate marginal Cox proportional hazards models. Results: A total of 48 patients who had prior head and neck radiation had 271 dental implants placed during May 1987 to July 2008. The estimated survival at 1, 5, and 10 years was 98.9%, 89.9%, and 72.3%, respectively. Implants placed in the maxilla were more likely to fail than implants placed in the mandible (p = .002).There was also a tendency for implants placed in the posterior region to fail compared with those placed in the anterior region (p = .051). Conclusion: Dental implants placed in irradiated bone have a greater risk for failure. Survival is significantly influenced by the location of the implant (maxilla or mandible, anterior or posterior).     

Oral implants in radiated patients: a systematic review

PURPOSE: Oral malignancy is often treated with a combination of surgery and radiation therapy (RT). The aim of this systematic review was to examine the effects of pre- and postimplantation RT on dental implant failure. MATERIALS AND METHODS: The literature published from 1990 through 2006 was reviewed for studies assessing pre- and postimplantation RT. Potential studies were identified by searches of PubMed, SCIRUS, and the Cochrane Central Register of Controlled Trials (CENTRAL). The incidence of implant failure has been linked to the following variables: post- versus preimplantation RT, site of implant placement, RT dose, delay from RT to implant placement, and timing of implant failure after placement. RESULTS: Similar failure rates were found for implants placed post-RT compared to those placed pre-RT (3.2% and 5.4%). In preimplantation RT, the implant failure rate was lower for the mandible (4.4%) in comparison to the maxilla (17.5%; OR = 4.63; 95% CI: 2.25 to 9.49). Other results did not reach statistical significance. No failures were observed in association with an RT dose lower than 45 Gy. All implant failures observed occurred within 36 months after RT, and most occurred between 1 and 12 months after placement. CONCLUSION: Notwithstanding the low number of implants evaluated, this review showed similar failure rate for implants placed post-RT and those placed pre-RT (3.2% and 5.4%, respectively).     

Smoking interferes with the prognosis of dental implant treatment: a systematic review and meta-analysis

AIM: This systematic literature review was performed to investigate if smoking interferes with the prognosis of implants with and without accompanying augmentation procedures compared with non-smokers. METHODS: A systematic electronic and handsearch (articles published between 1989 and 2005; English and German language; search terms "dental or oral implants and smoking"; "dental or oral implants and tobacco") was performed to identify publications providing numbers of failed implants, related to the numbers of smokers and non-smokers for meta-analysis. Publications providing statistically examined data of implant failures or biologic complications among smokers compared with non-smokers were included for systematic review. RESULTS: Of 139 publications identified, 29 were considered for meta-analysis and 35 for systematic review. Meta-analysis revealed a significantly enhanced risk for implant failure among smokers [implant-related odds ratio (OR) 2.25, confidence interval (CI(95%)) 1.96-2.59; patient-related OR 2.64; CI(95%) 1.70-4.09] compared with non-smokers, and for smokers receiving implants with accompanying augmentation procedures (OR 3.61; CI(95%) 2.26-5.77, implant related). The systematic review indicated significantly enhanced risks of biologic complications among smokers. Five studies revealed no significant impact of smoking on prognosis of implants with particle-blasted, acid-etched or anodic oxidized surfaces. CONCLUSION: Smoking is a significant risk factor for dental implant therapy and augmentation procedures accompanying implantations.